Purpose: Law enforcement may require police officers to inhibit intuitive responses to high threat and thereby affect their emotional reaction and operational effectiveness. Upon this premise, the current study reports two experiments which compare the impact of two relevant shot execution strategies on police officers’ shooting performance under high threat, including (1) fire at an armed assailant and then step away from the assailant's line of fire (‘fire-step’) or (2) step away from the assailant's line of fire and then fire (‘step-fire’). Method: In Experiment 1, 15 experienced police officers performed both shot execution strategies against a stationary assailant who occasionally shot back with coloured soap cartridges (high threat), while we measured their state anxiety, movement times and shot accuracy. In Experiment 2, the same 15 officers remained stationary and fired at the assailant who now performed both shot execution strategies in random order, thereby providing an indication of the risk (i.e., chance to get hit) associated with performing either strategy. Results: Experiment 1 showed that officers preferred using the step-fire strategy and that using this strategy resulted in lower levels of anxiety, increased time for aiming and more accurate shooting than the fire-step strategy. Experiment 2, however, indicated that the step-fire strategy also increases one's chance of getting hit. Conclusions: Findings suggest that inhibition of preferred responses under high threat (as in the fire-step strategy) may increase state anxiety and negatively affect shooting performance in police officers. Future work is needed to reveal underlying mechanisms and explore implications for practice.
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In this study, we examined the effects of a defender contesting jump shots on performance and gaze behaviors of basketball players taking jump shots. Thirteen skilled youth basketball players performed 48 shots from about 5 m from the basket; 24 uncontested and 24 contested. The participants wore mobile eye tracking glasses to measure their gaze behavior. As expected, an approaching defender trying to contest the shot led to significant changes in movement execution and gaze behavior including shorter shot execution time, longer jump time, longer ball flight time, later final fixation onset, and longer fixation on the defender. Overall, no effects were found for shooting accuracy. However, the effects on shot accuracy were not similar for all participants: six participants showed worse performance and six participants showed better performance in the contested compared to the uncontested condition. These changes in performance were accompanied by differences in gaze behavior. The participants with worse performance showed shorter absolute and relative final fixation duration and a tendency for an earlier final fixation offset in the contested condition compared to the uncontested condition, whereas gaze behavior of the participants with better performance for contested shots was relatively unaffected. The results confirm that a defender contesting the shot is a relevant constraint for basketball shooting suggesting that representative training designs should also include contested shots, and more generally other constraints that are representative of the actual performance setting such as time or mental pressure.
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Purpose: To examine the effects of different small-sided games (SSGs) on physical and technical aspects of performance in wheelchair basketball (WB) players. Design: Observational cohort study. Methods: Fifteen highly trained WB players participated in a single 5v5 (24-s shot clock) match and three 3v3 SSGs (18-s shot clock) on a (1) full court, (2) half-court, and (3) modified-length court. During all formats, players’ activity profiles were monitored using an indoor tracking system and inertial measurement units. Physiological responses were monitored via heart rate and rating of perceived exertion. Technical performance, that is, ball handling, was monitored using video analysis. Repeated-measures analysis of variance and effect sizes (ESs) were calculated to determine the statistical significance and magnitude of any differences between game formats. Results: Players covered less distance and reached lower peak speeds during half-court (P ≤ .0005; ES ≥ very large) compared with all other formats. Greater distances were covered, and more time was spent performing moderate- and high-speed activity (P ≤ .008; ES ≥ moderate) during full court compared with all other formats. Game format had little bearing on physiological responses, and the only differences in technical performance observed were in relation to 5v5. Players spent more time in possession, took more shots, and performed more rebounds in all 3v3 formats compared with 5v5 (P ≤ .028; ES ≥ moderate). Conclusions: Court dimensions affect the activity profiles of WB players during 3v3 SSGs yet had little bearing on technical performance when time pressures (shot clocks) were constant. These findings have important implications for coaches to understand which SSG format may be most suitable for physically and technically preparing WB players. DOI: https://doi.org/10.1123/ijspp.2017-0500 LinkedIn: https://www.linkedin.com/in/rienkvdslikke/ https://www.linkedin.com/in/moniqueberger/
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Paralympic wheelchair athletes solely depend on the power of their upper-body for their on-court wheeled mobility as well as for performing sport-specific actions in ball sports, like a basketball shot or a tennis serve. The objective of WheelPower is to improve the power output of athletes in their sport-specific wheelchair to perform better in competition. To achieve this objective the current project systematically combines the three Dutch measurement innovations (WMPM, Esseda wheelchair ergometer, PitchPerfect system) to monitor a large population of athletes from different wheelchair sports resulting in optimal power production by wheelchair athletes during competition. The data will be directly implemented in feedback tools accessible to athletes, trainers and coaches which gives them the unique opportunity to adapt their training and wheelchair settings for optimal performance. Hence, the current consortium facilitates mass and focus by uniting scientists and all major Paralympic wheelchair sports to monitor the power output of many wheelchair athletes under field and lab conditions, which will be assisted by the best data science approach to this challenge.
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Brochure from the Inauguration of Klaas Dijkstra, professor Computer Vision and Data Science
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The huge number of images shared on the Web makes effective cataloguing methods for efficient storage and retrieval procedures specifically tailored on the end-user needs a very demanding and crucial issue. In this paper, we investigate the applicability of Automatic Image Annotation (AIA) for image tagging with a focus on the needs of database expansion for a news broadcasting company. First, we determine the feasibility of using AIA in such a context with the aim of minimizing an extensive retraining whenever a new tag needs to be incorporated in the tag set population. Then, an image annotation tool integrating a Convolutional Neural Network model (AlexNet) for feature extraction and a K-Nearest-Neighbours classifier for tag assignment to images is introduced and tested. The obtained performances are very promising addressing the proposed approach as valuable to tackle the problem of image tagging in the framework of a broadcasting company, whilst not yet optimal for integration in the business process.
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Introduction: Nursing education traditionally teaches skill acquisition in isolated practice drills and guided by step-by-step protocols. While these approaches may seem to provide a solid foundation, they do not adequately bridge the gap between a controlled learning environment and the reality of nursing practice. The constraints-led approach (CLA) is an applied theory, which explains that skill acquisition is a process of adjusting to the characteristics of a situation, instead of reproducing isolated, “ideal” movements out of context. Given that CLA has gained recognition as an effective learning method in various fields, it is worth investigating how CLA can be implemented for skill acquisition in nursing education. Methods: To gain insight into student experiences of several CLA-exercises, an explorative qualitative design was used. Ten longitudinal focus groups with nursing students (n = 11) were performed to gain deeper understanding of students’ experiences with an education course in which several “CLA-exercises” were integrated. In addition, the teachers (n = 3) involved were interviewed after the course was completed. Results: The students experienced the education course as enjoyable, challenging and reality-based. Also, the exercises motivated students to keep practicing. The students further appreciated the room for autonomy and self-organization. The teachers expressed enthusiasm for CLA-inspired education, noting the benefits of varied methods and the need for expert feedback and well-working practice materials. Conclusion: Both students and teachers felt confident that the students who completed this course were ready to apply the learned skills under supervision in clinical practice.
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This study explores how non-executive directors are challenged by management while they seek to improve the effectiveness of supervisory boards in the Netherlands. A combination of semi-structured interviews and a questionnaire among non-executive directors indicates that supervisory board members mainly experience boardroom challenges in three core areas: the ability of non-executive directors to ask management critical questions, information asymmetries between the management and supervisory boards and the management of the relationship between individual executive and non-executive directors. The qualitative in-depth analysis reveals the complexity of the main contributing factors to problems in the boardroom as well as the range of process and social interventions non-executive directors use to address boardroom issues. The findings highlight the need to better understand boardroom processes and the need of non-executive directors to carefully manage relationships in and around the boardroom.
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In January 2017, relations between Greece and Turkey were under severe strain when warships from both sides engaged in a brief standoff near a pair of uninhabited Greek ‘islets’ in the Aegean, whose sovereignty is disputed by Turkey. Theoretically informed by the literature of foreign policy analysis, we examine how the Greek diplomats, military officers and political analysts interpreted Turkey’s behaviour at that particular time. The article considers the following research question: which factors, from a Greek point of view, explain Turkey’s foreign policy in the Aegean in January 2017? Our theoretical expectation is that, in the aftermath of the coup attempt in Turkey, Greek diplomats, military officers and political analysts would ascribe domestic calculations into Turkey’s activities. We employed Q- methodology to uncover socially shared perspectives on this topic. Based on our findings, we uncovered two viewpoints: (1) Turkey’s diachronic strategy in the Aegean and (2) the strongman style. According to the former and most widely shared viewpoint, a consistent ‘rationalist’ strategy to change the status quo in the Aegean explains Turkey’s behaviour. According to the second one, the belief system of Turkey’s leadership legitimises the use of force in the conduct of foreign policy.
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A model for programmatic assessment in action is proposed that optimizes assessment for learning as well as decision making on learner progress. It is based on a set of assessment principles that are interpreted from empirical research. The model specifies cycles of training, assessment and learner support activities that are completed by intermediate and final moments of evaluation on aggregated data-points. Essential is that individual data-points are maximized for their learning and feedback value, whereas high stake decisions are based on the aggregation of many data-points. Expert judgment plays an important role in the program. Fundamental is the notion of sampling and bias reduction for dealing with subjectivity. Bias reduction is sought in procedural assessment strategies that are derived from qualitative research criteria. A number of challenges and opportunities are discussed around the proposed model. One of the virtues would be to move beyond the dominating psychometric discourse around individual instruments towards a systems approach of assessment design based on empirically grounded theory.
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